LINQ 에서 컬럼 DBNULL 처리

LINQ 쿼리 작성 시  특정 컬럼에 DBNULL 값이 넘어와서 오류가 생길 경우 예외 처리 방법
 

 var ProductQuery = from a in dGroupData.TbProductList
                               select new Product
                               {
                                   G_ID = a.g_id,
                                   G_Sub_ID = a.g_sub_id,
                                   Item_ID = a.item_id,
                                   Item_Name = a.item_nm,
                                   Discount_Type = a.Isdiscount_typeNull() ? "0" : a.discount_type,
                                   Discount_Value = a.Isdiscount_valueNull() ? "0" : a.discount_value,
                                   Div_Sdt = a.div_sdt,
                                   Div_Edt = a.div_edt

                               };

Is+해당 컬럼+Null() 로 DBNULL 체크가 가능함

 Discount_Type = a.Isdiscount_typeNull() ? "0" : a.discount_type,
 Discount_Value = a.Isdiscount_valueNull() ? "0" : a.discount_value,